Server running Ubuntu 16.04.3, b2evolution 6.9.6. in a local network, behind a firewall.
Wanted to upload b2evolution from Win10 PC via FileZilla to local server.
Only 'home' directory seen on FTP, the /var/www/html are not visible.
Uploaded b2e dir and files to 'home' and sudo mv in server terminal to html.
Start install ok, after a while the blog was up and running.
But - I can not edit post and save it. Get error msg telling I have
no such privileges.
Installer was not able to save .htaccess file.
Yes, write and read access has somthing to do here but I am lost.
My wishlist:
I want FTP to be able to r/w direct to html dir, and as a user with admin
rights be able to edit the blog.
How and where do I set the correct w+r to obtain that?

That sounds like something you need to set in your Host Server Control panel (such as cPanel). Usually you will assign a user with privileges to the FTP. I would suggest you login to your control interface and see which user is assigned to the FTP account you are using, then check the users privileges/properties and set it accordingly.

More info:
Blog as a user has ' - - grant all privileges on *.* - - ' in the database.

I can connect to the server, move around, read and look at all default pics and delete posts and users in the blog, that is ok.
Altering setup, a new post or editing a post gives a errormsg when I try to save it.
I try alter the rights like this: sudo chmod 777 -R html.
Still I get errormsg like this:
Fatal error: Uncaught Error: Call to undefined function xml_parser_create() in /var/www/html/inc/xhtml_validator/_xhtml_validator.class.php:145 Stack trace: #0 /var/www/html/inc/_core/_param.funcs.php(2494): XHTML_Validator->__construct('posting', '1', '0', '0', '0', 'UTF-8') #1 /var/www/html/inc/_core/_param.funcs.php(2229): check_html_sanity('This is the lon...', 'posting', Object(User), 'utf-8') #2 /var/www/html/inc/collections/model/_blog.class.php(795): param_check_html('blog_longdesc', 'Invalid long de...') #3 /var/www/html/inc/collections/coll_settings.ctrl.php(110): Blog->load_from_Request(Array) #4 /var/www/html/admin.php(224): require('/var/www/html/i...') #5 {main} thrown in /var/www/html/inc/xhtml_validator/_xhtml_validator.class.php on line 145

More info:
Blog as a user has ' - - grant all privileges on *.* - - ' in the database.

I can connect to the server, move around, read and look at all default pics and delete posts and users in the blog, that is ok.
Altering setup, a new post or editing a post gives a errormsg when I try to save it.
I try alter the rights like this: sudo chmod 777 -R html.
Still I get errormsg like this:
Fatal error: Uncaught Error: Call to undefined function xml_parser_create() in /var/www/html/inc/xhtml_validator/_xhtml_validator.class.php:145 Stack trace: #0 /var/www/html/inc/_core/_param.funcs.php(2494): XHTML_Validator-&gt;__construct('posting', '1', '0', '0', '0', 'UTF-8') #1 /var/www/html/inc/_core/_param.funcs.php(2229): check_html_sanity('This is the lon...', 'posting', Object(User), 'utf-8') #2 /var/www/html/inc/collections/model/_blog.class.php(795): param_check_html('blog_longdesc', 'Invalid long de...') #3 /var/www/html/inc/collections/coll_settings.ctrl.php(110): Blog-&gt;load_from_Request(Array) #4 /var/www/html/admin.php(224): require('/var/www/html/i...') #5 {main} thrown in /var/www/html/inc/xhtml_validator/_xhtml_validator.class.php on line 145